Stepper exercise machine



FIG. 1 is a perspective view showing the new design for a stepper exercise machine.

FIG. 2 is a left view thereof;

FIG. 3 is a right view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines, if there are any, showing of portions of the stepper exercise machine depict environment and form no part of the claim. 

CLAIM The ornamental design for a stepper exercise machine, as shown and described. 